I have a fridge with a burnt out incandescent ligth globe. The original was 20W. I tried to replace it with a 5W LED, and it lit up for about 1 second, and then went off. The bulb works fine in a lamp, so I’m guessing I blew something in the fridge electronics?
My electronics knowledge is pretty basic, but I figured that using a lower wattage globe couldn’t really hurt. It at least wouldn’t have blown a fuse, right? Is there something else it could have done? LED control circuit HF feeding back into the fridge power circuit badly or something?
The rest of the fridge is working fine.
litchralee@sh.itjust.works 6 days ago
I’m taking a guess that perhaps the fridge makes similar assumptions that automobiles make for their lamps. Some cars that were designed when incandescent bulbs were the only option will use the characteristics resistance as an integral part of the circuit. For example, turn signals will often blink faster when either the front or left corner bulb is not working, and this happens to be useful as an indicator to the motorist that a bulb has gone bust.
For other lamps, such as the interior lamp, the car might do a “soft start” thing where upon opening the car door, the lamp ramps up slowly to full brightness. If an LED bulb is installed here, the issues are manifold: some LEDs don’t support dimming, but all incandescent bulbs do. And the circuit may require the exact resistance of an incandescent bulb to control the rate of ramping up to fill brightness. An LED bulb here may malfunction or damage the car circuitry.
Automobile light bulbs are almost always supplied with 12 volts, so an aftermarket LED replacement bulb is designed to also expect 12 volts, then internally convert down to the native voltage of the LEDs. However, in the non-trivial circuits described above, the voltage to the bulb is intentionally varying. But the converter in the LED still tries to produce the native LED voltage, and so draws more current to compensate. This non-linear behavior does not follow Ohm’s Law, whereas all incandescent bulbs do.
So my guess is that your fridge could possibly be expecting certain resistance values from the bulb but the LED you installed is not meeting those assumptions. This could be harmless, or maybe either the fridge or the LED bulb have been damaged. Best way to test would be installing a new, like-for-like OEM incandescent bulb and seeing if that will work in your fridge.
naught101@lemmy.world 6 days ago
Interesting! Thanks! I’ll see if I can find a similar bulb and try it.
I guess the fact that it worked for a second the first time and then stopped working entirely (but the bulb still works elsewhere) indicates I probably borked part of the fridge. Oh well, it wasn’t working for years anyway…